Extruder



W. G. BOND EXTRUDER Filed May 13. 1926 3 Sheets-Sheet 1 mam? W. G. EON

EXTRUDER Filed May 13. 1926 3 Sheets-Sheet 2 gwuentoz:

EXTRUDER Filed May 13. 1926 3 Sheets-Sheet 3 inders and sheet asbestos'and by corrugating Pntente or.. 29, rear.

WILLIAM GJBOND, F WILMINGTON, DELAWARE.

EXTRUDER.

Application filed May 13,

This invention relates to the manufacture of articles of cork or other similar material and has for its principal objects the provision of a simple and eflicient machine for producing such articles, an improved method of extruding cork or other material, and an article of cork or other material of similar nature in which a great number of dead air spaces are provided which spaces may be filled with carbon dioxide in place of air whereby to increase the resistance of the article to burning.

It is highly desirable under many circumstances to form an article of comminuted material and a binder in which the weight shall be as slight as possible In making articles of asbestos this feature is accomplished-usually by forming concentric cylsheets between the cylinders so as to provide dead air spaces. Itywould be possible to form cork cylinders having holes extending entirely thru the cork article but if the holes could be of short length, broken by reenforcing elements, the strength of the material would be very greatly increased without too materially affecting the total weight.

it is one of the objects of the present invention to provide an article suitable for heat insulation and having a multiplicity of dead air spaces therein of rather slight size so that there is no longitudinal line of weakness against crushing as would be the case if the bores were continued thruout the length of the article. For convenience of illustration the article has been shown in the drawings asbeing a'cylinder but it must be remembered that the invention pertains broadly to the provision of the air, gas, or liquid filled cells and that the article may well be a half cylinder (in which case no mandrel is required) or may be sheet material. lhe material if made in sheet form will serve very excellently as a heat insulating lining for a house particularly for a wooden house, and it is the intention to apply this lining directly to the framing and to apply the plaster directly'to the sheets of cork material.

A feature of the present elimination of the constant stopping whic occurred in the old type machines by reason or the cork following the plunger as it invention is the raised or receded in hot weather, this following of the cork stopping the proper feeding.

0% Way to correct this trouble in. the old- 1926. Serial No. 108,374.

machines was by passing a greatly increased volume of cold Water thru thechilling chamhere, the amount of water being determined bythe' cut and try method, that is, the flow was increased until the following of the cork Was minimized. 'By providing a screw feed for the cork a great saving in the cost of the cooling water may be made and the feed is much surer under any and all circumstances. lln using the screw conveyors the cork is kept under compression at all times as when the screw conveyers are used the plunger is never permitted to leave the forming tube.

In the drawings Figure l is a front elevation of one form of machine for carrying out the process.

Figure 2 is a side elevation.

Figure 3 IS a crosssection thru-one of the forming tubes. f

Figure 4 is a detail of the screw feed. Figure 5 is a section thru the mandrel. Figure 6 is a fragmentary radial section thru the article showing the air cells.

Figure 7 is a modification. The machine ispreferably and is here shown as having a cast frame including a pair of heavy iron sides .10 braced by horizontal ribs such as ll, 12 and 18, the latter forming the base or bed. Each of the sides are extended forwardly as at 14 to provide guides 15 for the main cross head 16 which is reciprocated by a pitman 17 pivoted to a crank wheel 18 driven from a source of power, here shown as a pulley wheel 20, preferably by a train of reducing gears as shown in Figure 2. It will be readily understood that the specific form of embodiment of the invention illustrated is h circular in cross section and fits a cylindri' cal forming tube 23 threaded into the hopper 25 as at 26, the hoppen being tast to each frame side 10 and may in fact be integral therewith.

of sturdy type I gearingfor reciprocating the cross head '16 as head 16 is actually of consider-f icet e pl nger 22 is been a as a.

figuration to receive slidably a plurality-of hollow tubes 30, the number of which vary with the diameter of the plunger. The tubes may be of any desired size but I find 1t convenient to make the tubes about an eighth of an inch in diameter over all and to space the tubes about an eighth of an inch apart in concentric circles. The tubes are loosely and slidably mounted in a cross head 32 but have lock nuts at their top so that the raising of the cross head 32 will lift the tubes altho the lowering of the cross heads will not necessarily lower the tubes. It is the intention that the tubes shall at all times extend below the plunger, and that their length of travel will be such as to cause them to move between proper coagulation and non-coagulation points.

To each forming tube 23 is secured a pluralit of hollow castings numbered 34 to 37 of w ich 34 and 35 are cold chambers whereas the large intermediate chamber 36 is hot as is also the final chamber 37. The meansfor heating and chilling these chambers may conform to any known practice as for example, the cold chambers 34 and 35 may have water outlets 39 and water inlets 38, each preferably controlled by an independent valve 40 while the hot chambers may have steam inlet pipes 42 controlled by valves 43 and steam outlet pipes 44 since heating by steam is in my OPIDIOII preferable where the size of the article is reasonably large. The chambers may naturally be electrically heated in the same manner as I have shown the central mandrel. It will be noted that the heating and chilling chambers in the mandrel do not register wit-h each other. This is because the radial depth of the cork between the mandrel and the top is relatively small. Should the radial distance between the tube and the mandrel be relatively great the hot zones would register.

The mandrel is hollow and is supported from the frame and has no relative movement with respect thereto. The mandrel tube is capped at the bottom as at 51 and at the top as at 52 and in addition has securedto it near the bottom a spooLlike casting 54 wh1ch divides the bore of the mandrel into three compartments, the upper and lower compartments being cold chambers while the intermediate com artment defined by the disks or ends of the casting 54 is a heating compartment, preferably heated by electric resistance elements wound about the sleeve of the castin 54. The current carrying wires 56, inclu ing naturally a variable resistance element 57, are conducted .to the heating chamber of the mandrel thru a pipe 59'to protect the wires against the water in the upper compartment 60. I find it unnecessary m mostcases torovide two inlets for cold water to the man rel as I find that one, Such as 61,.1s-sufilcient, Thi pipe delivers cold water to the upper chamber and a second pipe 63 leading thru the casting 54 discharges the water from the upper chilling compartment 60 to the lower and warmer chilling compartment 65. A pipe 66 controlled by a valve 67 discharges the water from the bottom compartment while a separate pipe 68 controlled by a valve 69 discharges the water from the upper cham her.

higher there would be danger of the heat traveling up the wall of the mandrel and making the binder sticky. While under some circumstances it might possibly be advantageous to add a bottom and relatively small heating chamber to the mandrel, in practice I do not find it necessary at all and believe that under almost all circumstances the three chambers as shown in the drawings will be satisfactory for all purposes. The tem erature of the bottom cold chamber 65 of t e mandrel is regulated so that the annular articles of cork, or whatever material may be used, are discharged with minimum tendency to distort in order that the usual step of shaving may entirely be omitted.

While I have shown a conventional hopper 25 I may under certain circumstances do all of the feeding thru the screw conveyers 80. 'These screw conveyers are of old and well known type and form per se no part of the invention except in combination, and particularly the use of a screw conveyer with a stationary breaker plate 81. I find these screw conveyers very convenient as they give an absolutely steady pressure to the cork.

A hood 82 is secured to each cross head and is of sufficient height to permit the various tubes 30 to move freely the amount of the'raise of the cross head 32 by means of the cam 84 on a shaft 85 which is constantly or intermittently driven (as desired) from vertical shaft 86 connected by a beveled gear 87 with the main crank wheel 18., A pipe 90 leads to the hood 82 and delivers a liquid or gas preferably the latter. It is my intention to use carbon dioxide as the gas, since this gas is noninflammable. A valve 92 which may be operated intermittently controls passage of the gas or liquid thru the tubes 30 to the forming tube 23, in which case it is not necessary to move the tubes 30.

The operat on of the device is as follows;

teac er The finely divided material which may .for example be granulated cork, treated with a binder of the general type used but more preferably of a phenol condensation product 0 is fed into the hopper or in case the screw conveyers are used into this hoppers 94 for the screw conveyers 80. he plunger 22 is reciprocated thru the pitman 17 and packs the cork'between the forming tube 23 and the mandrel 50. The plunger never withdraws completely out of the forming tube 23 it the screw conveyers are used andit acts to break up the discharge from the worm conveyors. In using the worm I find it important to mount a perforated disk 81 in the end of the screw conveyor tube in exactly the same fashion as the end of a food chopper is perforated. This non-rotatable disk at the end of the tube acts to break up the feed and entirely eliminates the spiral stratification so characteristic of previous and un successful use of a' screw conveyer packing in the cork art and allows use of the screw alone without the plunger.

The shaft 85 18 so geared that it makes only one revolution to eight or more reciprocations of the plunger. The cam L84 has but a single surface and it serves toraise the cross head and to carry with it-the tubes but the cross-head does not carry the tubes i down with it, these descending by gravity and by the pull of the cork about their lower ends. Airs the tubes move down they form pockets in the cork and as they move'sharply e up carbon dioxide or other material is forced down thru the tubes so as to preserve these holes which then become air or gas cells giving a very excellent form of heat insulation and one admirably suited to pipe covering particularly if the finely divided material be or include a material of the general nature oi asbestos. It will be noted that the lower ends of the tubes-which are shown up in the drawings, at all times extend below the upper surface of the heating chambers 36 so as to minimize the tendency or the cork, asbestos, sawdust or whatever else may be used to close the air or carbon dioxide cells.

in Figure? l have shown,a;.moditication which is highly advantageousdor making certain types of molded articles. In this figure the forming tube 110 has the usual "chilling and heating zones 111 and 112 secured to and carried by the tube 110 which preferably is fast to the hopper 114. A screw conveyer or worm. 115 feeds the coinminuted material and hinder thru a breaker plate 116 having a plurality of openings 11? therein and keeps the material under constant pressure. The mandrelllu is optional is naturally used whenever there is'to be an openingin: the formed article. The mandrel is diagrammatically illustrated in this figure and may be of any preferred type.

.. slow. When the feed is slow the'binder sets about the tubes so that when the comminuted material and binder pass the lower end of the tubes the hole remains in the molded article but when-the next alternate fast feeding occurs the particles and binder pass the end of the tube before the binder is set and the material therefore expands at the bottom of the tube and closes the just-formed air cell. In this way ll form a number of series of air cells equal to the number of tubes 120 but in each series the air cells are relatively short.

What l claim is 1. The process of forming a molded article which consists in forcing comminuted particles and a binder thru a passage, compressing the particlesfsubjecting the compressed particles to heat, intermittently delivering.

a gas to the heated particles to form cells and finally cooling the particles while still compressed.

2. The process of forming a molded article which consists in forcing comminuted cork and a binder thru a tubular passageway, having in its entrance end a plurality of hollow pipes, compressing the cork in the passageway about said pipes, subjecting the compressed particles to heat at a point above the end of the pipes, delivering matterthru the pipes to form cells in the molded article and in cooling the particles while still compressed.

3. In a device of the character described, aiiorming tube, a plurality of alternate chilling and heating chambers surrounding said forming tube, a mandrel centrally positioned in the tube, a plunger fitting said tube and mandrel V and having a plurality of bores therein and a plurality of rods loosely mounted in said bores, means for reciprocating said plunger and means for intermit; tently raising said rods.

4 4k. ln a device of the character described,

very convenient way of forming the loo rocating plunger having a plurality of bores therein, a plurality oil tubesv extending in the bores oi said plunger and means for raising said tubes.

5. in a device of the character described,

a forming tube, alternate chilling and heating zones surrounding said tube, a recipro-' eating plunger having a plurality of bores therein, and means for discharging thru said 5 Secured to the breaker plate 116 are a liores and into the nu. tube a gas to fogm gas cells in an article molded in the tu e.

6. Ina device of the character described, a formlng tube, having alternate heating and chilling zones, a plunger reciprocatingly mounted in said tube, a plurality of tubes extending thru said plunger and into the forming tube within said heating zone and means for intermittently delivering a gas thru said tubes.

7. The device of claim 6 in which means arg provided for intermittentlyraising said tu e.

8. In a device of the character described, a forming tube having a plurality of alternate cooling and heating zones, a mandrel within said tube having cooling and heating zones therein, the number of zones in the mandrel being less than the number of zones 'in the forming tube.

9. In a device of the character described, a forming tube, having four alternate coolin and heating zones, a mandrel within sald tube having three zones, the initial and end zones of the mandrel being cooling while the intermediate zone is a heating zone.

10. The device of claim 9 in which the heating zone of the mandrel is nearer the exit end of the tube than the initial heating zone of the tube.

11. In a device of the character described, a forming tube having a plurality of alternate heatlng' and cooling zones, a screw conveyer discharging into one of the cooling zones and a reciprocating plunger in said forming tube having its axis at an angle to the axis of the screw conveyer.

12. In a device of the character described, a forming tube having alternate cooling and heating zones, a mandrel having alternate heating and cooling zones, a plunger fitting said mandrel and said tube, a plurality of tubes extending] thru said plunger, means for simultaneously raising said tubes and means for discharging a gas thru said tubes as they are raised whereby to form air polcjkets in an article molded in the forming tu e.

13. As an article of manufacture, an extruded insulating material composed of colnminuted material and a heat-coagulated binder, in which a plurality of elongated cells are provided.

14. The article of claim 13 in which the cells are in a plurality of axially aligned series.

- 15. The process of forininga molded article which consists in forcing comminutcd particles and a binder thru a plurality of openings into a passageway. whereby the particles are compressed, and in subjecting the compressed particles to alternate heating and cooling zones while still compressed in the passageway.

16. The process of forming a molded article consisting in forcin with a steady pressure comminuted partic es and a binder thru a plurality of openings into a passageway having heating and cooling zones.

17. The process of forming air cells in a molded article formed from comminuted particles and a binder which sets when heated which consists in forcing the particles and binder thru a. passageway having heating and cooling zones and having a plurality of cell forming obstructors therein which consists in alternately feedin the material so slowly that the binder will set about the end of the cell forming obstructions and so rapidly that the binder will not have time to set and will close the cavity formed by the obstruction beyond the end of the obstruction.

. 18. In a device of the character described, a forming tube having alternate cooling and heating zones, a perforated breaker plate within the tube, a screw conveyer feeding thru the holes in the breaker plate to the tube, and a plurality of rods suspended from said plate.

19.'The device of claim 18 in which the rods are hollow.

20. The device of claim 18 in which the rods are hollow and the screw is intermittentl driven so as to form series of separate air cells in the molded product.

In testimony whereof I aiiix my signature.

WILLIAM G. BOND. 

